背景:本研究旨在评估巴基斯坦6个月至15岁的HIV感染儿童在TCV疫苗接种后几个时间点的血清学应答和血清转换率的寿命。
方法:从2020年11月20日至2021年1月2日,共纳入336名儿童,并进行为期12个月的前瞻性随访。在给药TCV之前和4-6周收集血液样本,6个月,和给予单剂量(0.5ml)肌内TypbarTCV®后1年。使用ELISA分析样品的抗Vi-IgG抗体。几何平均滴度(GMT),血清转换率(抗Vi-IgG从基线上升四倍),使用广义线性混合模型评估了与1年时持续血清转换相关的因素。
结果:与>5岁的儿童相比,6个月至5岁的儿童的血清转换率显着降低;在6个月时(127/216(58·8%)对(81/111(73·0%)),在1岁时(110/217(50·7%))对(78/109(71·6%)),只有三分之二;188/326(57·7%)在1年时保持血清转化。与>5岁的儿童相比,6个月至5岁的儿童的GMT(95%CI)显着降低,6个月时9·6(7·6,12·0)对28·9(20·2,41·4),在1年时间点,6·6(5·4,8·0)与23·1(16·4,32·5)。持续血清转换的几率随时间显着降低(调整后的优势比(aOR):0·232;95%CI:0·136,0·396)。在非严重HIV临床疾病患儿(aOR:10·6;95%CI:1·5,73·9)和年龄较大的儿童(aOR:7·45;95%CI:11·2,47·0)中,TCV疫苗接种1年后持续血清转换的几率显著增高。
结论:感染HIV的儿童在接受TCV治疗一年后血清转化率下降。在患有严重或晚期HIV疾病的儿童中,下降幅度显着。TCV给药后一年,感染HIV的儿童血清转换率显着下降。
BACKGROUND: This study aimed to assess the longevity of serologic response and seroconversion rates at several time points following TCV vaccination among children living with HIV aged 6 months to 15 years in Pakistan.
METHODS: From November 20, 2020, to January 2, 2021; 336 children were enrolled and followed up prospectively for 12 months. Blood samples were collected before the administration of TCV and at 4-6 weeks, 6 months, and 1 year after administration of a single dose (0.5 ml) of intramuscular Typbar TCV®. Samples were analyzed for anti-Vi-IgG antibodies using ELISA. Geometric mean titers (GMTs), seroconversion rates (fourfold rise in anti-Vi-IgG from baseline) were assessed, and factors associated with sustained seroconversion at 1 year were evaluated using generalized linear mixed models.
RESULTS: The seroconversion rates were significantly lower in children aged 6 months to 5 years compared to children > 5 years; (127/216 (58·8%)) versus (81/111 (73·0%)) at 6 months and (110/217 (50·7%)) versus (78/109 (71·6%)) at 1 year, only two-third; 188/326 (57·7%) remained seroconverted at 1 year. The GMTs (95 % CI) were significantly lower in children aged 6 months to 5 years compared to children > 5 years, 9·6 (7·6, 12·0) versus 28·9 (20·2, 41·4) at 6 months, and 6·6 (5·4, 8·0) versus 23·1 (16·4, 32·5) at 1 year time point. The odds of sustained seroconversion significantly decreased with time (adjusted odds ratio (aOR): 0.23; 95 % CI: 0.14, 0.40). The odds of sustained seroconversion following 1 year of TCV vaccination were significantly higher among children with non-severe HIV clinical disease (aOR: 10·61; 95% CI: 1·52, 73·98) and children in elder age group (aOR: 7·45; 95% CI: 1·18, 47·03).
CONCLUSIONS: A significant decrease in seroconversion rates was observed among children living with HIV following one year of TCV administration. The decline was significantly higher in children with severe or advanced HIV clinical disease and children younger than five years of age.